Not Applicable
Not Applicable
Percutaneous transluminal coronary angioplasty (PTCA) is a procedure which is well established for the treatment of blockages in the coronary arteries. Blockages may occur from cholesterol precipitation on the coronary wall which may be in any stage from initial deposit through aged lesions. Coronary arteries may also become blocked due to formation of thrombus.
The most widely used form of percutaneous coronary angioplasty makes use of a dilatation balloon catheter. In typical PTCA procedures, the cardiovascular system of a patient is accessed with an introducer, usually in the groin area. All other devices including a guiding catheter are percutaneously introduced into the cardiovascular system of a patient through the introducer and advanced through a vessel until the distal end thereof is at a desired location in the vasculature. A guide wire and a dilatation catheter having a balloon on the distal end thereof are introduced through the guiding catheter with the guide wire sliding through the dilatation catheter. The guide wire is first advanced out of the guiding catheter into the patient""s coronary vasculature and the dilatation catheter is advanced over the previously advanced guide wire until the dilatation balloon is properly positioned across the lesion. Once in position across the lesion, the flexible, expandable, preformed balloon is inflated to a predetermined size with a fluid at relatively high pressures, such as greater than about four atmospheres, to radially compress the atherosclerotic plaque of the lesion against the inside of the artery wall and thereby dilate the lumen of the artery. The balloon is then deflated to a small profile so that the dilatation catheter may be withdrawn from the patients vasculature and blood flow resumed through the dilated artery.
In angioplasty procedures of the kind described above, there may be restenosis of the artery, which either necessitates another angioplasty procedure, a surgical by-pass operation, or some method of repairing or strengthening the area. To reduce restenosis and strengthen the area, a physician can implant an intravascular prosthesis for maintaining vascular patency, called a stent, inside the artery at the lesion. In general, stents are prosthetic devices which can be positioned within a body cavity, for example, a blood vessel of the body of a living human or in some other difficulty accessible place. A stent generally has a diameter which may be increased or decreased. Stents are particularly useful for permanently widening a vessel which is in a narrowed state, or for internally supporting a vessel damaged by an aneurysm.
Such stents are typically introduced into the body cavity by use of a catheter. The catheter is usually of the balloon catheter type in which the balloon is utilized to expand the stent, which is positioned over the balloon, to place it in a selected location in the body cavity. The stent is expanded to a larger diameter for placement in the vasculature, often by the balloon portion of the catheter.
One important characteristic of a dilatation balloon catheter is its xe2x80x9cprofilexe2x80x9d, which is determined by the outer diameter (O.D.) of the distal end portion of the balloon and stent when deflated. The outer diameter affects the ease and ability of the dilatation catheter to pass through a guide catheter, through the coronary arteries, and across a tight lesion.
Minimization of xe2x80x9cprofilexe2x80x9d is of importance in balloon catheters and stent delivery systems. Accordingly, the present invention is particularly directed to a novel balloon protector which retains the balloon catheter in a reduced configuration prior to insertion of the catheter into a body lumen. The balloon protector of the present invention is suitable for use with a balloon catheter equipped with or without a stent.
A second important characteristic of a dilation balloon catheter is preventing damage to the catheter prior to insertion. It is known in the percutaneous balloon delivery art that the balloon or inflatable portion of a catheter may be easily damaged or ruptured prior to insertion into the body. Furthermore, preparation and associated manipulation of the balloon and /or stent prior to catheter insertion may impair balloon performance and possibly compromise the otherwise sterile condition of the catheter surface.
Protecting the catheter, especially the balloon, from damage and maintaining a sterile field about the catheter prior to insertion is of significant importance in any medical procedure involving a catheter. Accordingly the present invention is also directed to a novel balloon protector which has sufficiently strong and thick walls to protect the balloon from damage such as accidental puncture and that may be fitted over a balloon catheter with or without a stent, immediately after manufacturing and preparing the catheter for use.
The present invention is directed to a balloon protector for use an a variety of balloon catheter types. More specifically, the present invention is directed to a protector tube having a pre-kinked portion. A sterile balloon catheter is drawn through a die containing the tube, the ends of the tube are then drawn outwardly thereby drawing the pre-kinked area of the tube down against the balloon catheter.
This invention provides for a diameter reducing balloon protector for use in shielding the various components of an implantable balloon catheter from damage such as puncture, as well as for providing the balloon catheter with a maintainable sterile field prior to use. The present balloon protector when drawn down about a balloon catheter has sufficient strength and thickness to maintain the balloon catheter (and an associated stent if desired) in a reduced configuration prior to inserting the catheter into a body lumen. The present balloon protector may be easily fitted to nearly any variety or size of balloon catheter with minimal cost and effort.
In order to provide the balloon protector with a means of being removed from the balloon catheter, the inside diameter of the balloon protector may be treated with a variety of lubrications such as a slip coat.